explain chapter...body fluid and circulation of class 11 in a way of flowchat ..
❌STOP COPING FROM INTERNET ❌
Answers
HOPE IT HELPS YOU DEAR......⤴️⤴️
FOLLOW ME
Body fluids are the medium of transport of nutrients, oxygen and other important substances in the body.
Blood is the most commonly used body fluid in most of the higher organisms. Lymph also transports certain substances like protein and fat.
Blood is a fluid connective tissue composed of a fluid matrix, plasma and the blood corpuscles. It forms about 30-35% of the extracellular fluid. It is slightly alkaline fluid having pH7.4.
Plasma is straw coloured viscous fluid that constitutes 55% of blood volume. It consists of 90-92% water, 6-8% protein (fibrinogens, albumins and globulins), glucose, amino acids and small amount of minerals like Na+, Ca++, Cl– etc.
Erythrocytes, leucocytes and platelets are collectively called formed elements.
Erythrocytes are most abundant cells in human body. Total blood count of RBCs is 5-5.5 million, which is slightly less in females due to menstruation. It is formed in bone marrow. Nucleus is absent in mammalian RBCs having biconcave shape.
Every 100 ml of blood contain 12-16 gm. of haemoglobin. They have life span of 120 days. They are destroyed in spleen( graveyard of RBCs)
Leucocytes or WBCs are colourless due to absence of haemoglobin. 6000-8000 of WBCs are present in each ml. of blood.
Neutrophils are most abundant and basophils are least abundant WBCs. Monocytes and neutrophils are phagocytic cells which destroy foreign organisms.
Basophils secrete histamine, serotonin and heparin that are involved in inflammatory reactions.
Eosinophils resist infection and allergic reactions. B and T lymphocytes are responsible for immune response of the body.
Thrombocytes or platelets are cell fragments produced from megakaryocytes in bone marrow. 150000-350000 platelets are present in each ml of blood. Platelets are involved in clotting or coagulation of blood in case of injuries.
Blood Groups – blood of human beings differ in certain aspects although it appear same in all individuals. Two main types of grouping are ABO and Rh.
ABO grouping is based on presence or absence of two surface antigens RBC, antigen A and antigen B. The plasma of an individual also contains two antibodies produced in response of antigens.
During blood transfusion, blood of donor has to be matched with blood of recipients to avoid clumping of RBCs.
Group ‘O’ blood can be donated to any individual with any blood group, so it is called universal donor.
Person with ‘AB’ blood group can receive blood from any person of any group, so it is called universal recipient.
Rh grouping – Rh antigen (similar to Rhesus monkey) are observed on surface of RBCs of majority of individuals (about 80%). Such people are called Rh positive () and those in whom this antigen is absent are called Rh negative ().
Coagulation of blood (Blood Clotting)
When an injury is caused to a blood vessel bleeding starts which is stopped by a process called blood clotting. An injury or trauma stimulates the platelets in the blood to release certain factors that activate the mechanism of coagulation. Calcium play important role in blood clotting.
Lymph
It is a colourless fluid containing specialized lymphocytes that provide immune response to body.
Human Circulatory System – consists of 4 chambered muscular heart, closed branching blood vessels and circulatory fluid blood.
Heart is the mesodermally derived muscular organ, present in thoracic cavity between the two lungs protected by double membrane of pericardium.
The upper two chamber is called atria and lower two chambers are called ventricles. Interatrial septum separate the right and left atrium and thick walled inter ventricle septum separate the ventricles.
The opening between right atrium and right ventricle is guarded by a three muscular flaps called tricuspid valve. Bicuspid or mitral valve guards the left atrium and ventricle.
The opening of right and left ventricle to pulmonary artery and aorta respectively is controlled by semilunar valve.
The nodal tissue present on upper right corner of right atrium is called SAN (sino-atrial node) and those on lower left corner of right atrium is called AVN ( atrio-ventricular node).
The purkinje fibres along with right and left bundles form the bundle of HIS. The nodal musculature has ability to generate action potential.
SAN generate maximum number of action potential and is responsible for rhythmic contraction of heart. Therefore it is called pace maker.
The P-wave represents the electrical excitation of atria (depolarisation) which leads to contraction of atria.
The QRS-wave represents the depolarisation of ventricles, which initiates the ventricular contraction.
The T-wave represents the return of ventricle from exited to normal state (repolarization). The end of T-wave marks the end of systole. Counting the number of QRS complex in given period of time determine the heartbeat rate